The author focuses on the age span of 12 through 18, the time that most American youth spend in junior or senior high school and the period when violence and substance abuse most often begin. Although the rates of these behaviors do not change drastically when youth turn 19, this end point is useful because it marks the beginning of a rapid decline in typical adolescents' dependency on their parents. Adolescents' lives change dramatically, and there are sharp increases in rates of marriage, parenthood, fulltime employment, and independent residence. In his research on violence and the use of alcohol and drugs by minors, the author distinguishes violence directed at persons from offenses against property, especially theft. He focuses more on violent behavior than on victimization from violence. His approach to the subject diverges from previous reviews in two ways: (1) He reviews demographic patterns of rates of violence and substance use to establish the similarity of these phenomena as social problems; and (2) He compares the relationship of violence and substance use to other relationships among deviant or problem behaviors to clarify both the implications of the relationship and its likely sources. References, footnotes, tables